Experimental and numerical analysis of sustainable recycling of sheet metal products

Industrial production growth within the last decades has led to increase in the amount of material and energy consumed by the industry. This has accelerated the movements towards the idea of sustainable manufacturing. As a result, significant amount of effort is directed into research and developments of new technologies and strategies to enhance sustainability index in industrial activities. Amongst all, the idea of reusing or cold recycling is an emerging phenomenon within a variety of industrial scheme. Specifically in the area of sheet metals cold recycling lacks dedicated researches. Since sheet metal forming offers great amount of contribution in metal industry, it has high potential to encourage the study on possibilities of cold recycling instead of conventional recycling through melting. This thesis represents a study on aspects of cold-recyclability of sheet metal products with a concentration on assessments of residual formability. In this research Re-formability index as a new terminology was introduced to characterize the re-formability of an existing formed material. The proposed method takes advantage of latest technique to deal with multiple path forming. This re-formability index accounts for possible level of formability in different strain paths based on newly introduced Polar Effective Plastic Strain (PEPS). Experimental investigation on an existing cold roll forming process is taken as case study. Extensive microhardness test in conjunction with advanced techniques in finite element simulation has been major part of this research. The significance of this work is movement towards recycling of sheet metal products without melting them and would contribute to energy saving by facilitating design for sustainability. A software called 'REFORMAP' was developed to implement the residual formability mapping. This code operates downstream of the finite-element simulation of forming process. So the FEA results get post processed in this code to obtain specific analysis on re-formability index.